Vibrating tables are conventionally employed for various uses, particularly the mixing between liquids, the compaction of powders or grains, the degassing and fluidification of concrete when it is cast for moulding prefabs or posts in civil engineering.
A vibrating table with vertical acceleration generally comprises a rigid frame presenting a substantially vertical axis and a base, and intended to surround said object, a damping device (comprising springs and dampers) isolating said base from the ground, and a device with vertical oscillations connected to said frame so as to entrain said table in a vibratory movement.
In the prior art, the object is either placed on or attached to the vibrating table, without any particular precaution, as the accelerations or displacements carried out are relatively weak.
The invention relates more particularly, but not exclusively, to a vibrating table with vertical acceleration for an object consisting in a recipient having to be homogeneously filled with a material, intended to encase nuclear waste for example, and to the use of such a vibrating table in a process for filling this recipient.
In certain particular applications, particularly but not exclusively in the case of processing contaminated waste coming from the nuclear industry, it is necessary, in order to obtain the desired result of fluidification and of degassing of the material, to subject the vibrating table to a vibratory movement having a relatively great vertical acceleration under a high frequency.
In these scenarios, the recipient placed on the vibrating table must be held with considerable precaution so that, on the one hand, it cannot move during the vibratory phase of the vibrating table and, on the other hand, it does not undergo physical damage capable of rendering it fragile.
Thus, in the particular case of processing contaminated waste issuing from the nuclear industry, no vibrating table which correctly responds to the existing constraints, exists. For this application, the vibrating table should make it possible to fluidify and degas the concrete intended to encase the cases containing the waste, these cases being positioned inside the recipient placed on the vibrating table. The concrete is cast in the recipient during the vibratory phase of the vibrating table and all the air pockets in the concrete must be evacuated out of the recipient in order to ensure optimum encasing then subsequent storage of the waste contained in the recipient.
To that end, the recipient must be perfectly clamped on the vibrating table while avoiding any shock which might cause damage compromising its long-term tightness.
It is therefore an object of the invention to provide a vibrating table with vertical acceleration which responds to the criteria which have just been described hereinbefore, in order to allow an object, such as a recipient, to be sufficiently blocked, while ensuring that it does not suffer any damage while the vibrating table is being used.